interior angle

American  

noun

Geometry.

1. an angle formed between parallel lines by a third line that intersects them.

2. an angle formed within a polygon by two adjacent sides.

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interior angle British  

noun

1. an angle of a polygon contained between two adjacent sides

2. any of the four angles made by a transversal that lie inside the region between the two intersected lines

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interior angle Scientific  

/ ĭn-tîr′ē-ər /

1. Any of the four angles formed inside two straight lines when these lines are intersected by a third straight line.

2. An angle formed by two adjacent sides of a polygon and included within the polygon.

3. Compare exterior angle

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Etymology

Origin of interior angle

First recorded in 1750–60

Example Sentences

Each interior angle of a regular heptagon is a bit over 128 degrees, so when we put three of them together at a vertex, we get more than 360 degrees.

From Scientific American • Nov. 17, 2013

I got the first cut, but again, when I started cutting the interior angle, the bar worked its way out of the jig, and the tool dug in and broke.

From "October Sky" by Homer Hickam

A groove to the left of the group seems to show that this slab was at an interior angle of a building.

From A Catalogue of Sculpture in the Department of Greek and Roman Antiquities, British Museum, Volume I (of 2) by Smith, A. H.

June.—Opposite, joining the interior angle ones of Haggai.

From Our Fathers Have Told Us Part I. The Bible of Amiens by Ruskin, John

Its oldest form resembled an English V with a straight line running up bisecting its interior angle.

From A Plain Introduction to the Criticism of the New Testament, Vol. I. by Scrivener, Frederick Henry Ambrose